clk: let of_clk_get_parent_name() fail for invalid clock-indices
Currently, of_clk_get_parent_name() returns a wrong parent clock name
when "clock-indices" property exists and the target index is not
found in the property. In this case, NULL should be returned.
Currently, of_clk_get_parent_name(consumer_np, 0) returns "clka"
(and of_clk_get_parent_name(consumer_np, 1) also returns "clka",
this is correct). Because the "clock-indices" in the clock parent
does not contain <0>, of_clk_get_parent_name(consumer_np, 0) should
return NULL.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>